Well, the results are in: Cyber Monday has come and gone, and guess what? It was the biggest online shopping day ever in the U.S., according to analytics firm comScore. Not only were ecommerce sales up 17 percent from last year, they reached $2.04 billion, the first time online sales have surpassed $2 billion in a single day. (While this is undoubtedly good news for U.S. retailers, to put things in perspective, Chinese ecommerce giant Alibaba surged past $6 billion in online sales during its annual Singles' Day event this November).

"Any notion that Cyber Monday is declining in importance is really unfounded, as it continues to post new historical highs and reflects the ongoing strength of online this holiday season," Gian Fulgoni, comScore's co-founder and executive chairman, said in a statement.

"Varying reports have also indicated weakness in the consumer economy due to flagging brick-and-mortar sales over the holiday weekend, but what we may really be seeing is an accelerating shift to online buying as mobile phones spur increased showrooming activity," he continued. "The data we're seeing suggest it may be more a change in shopping behavior than a lack of consumer demand."

In terms of online sales, Cyber Monday marked Walmart's most successful day in the retailer's 50-plus year history, Fortune reports.